package com.example.myapplication1;

import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;


public class DBHelper extends SQLiteOpenHelper {
    private static final int VERSION = 2; // 版本号升级
    private static final String DB_NAME = "myrate.db";
    public static final String TB_NAME = "tb_rates";

    public DBHelper(Context context) {
        super(context, DB_NAME, null, VERSION);
    }

    @Override
    public void onCreate(SQLiteDatabase db) {
        db.execSQL("CREATE TABLE "+TB_NAME+"(ID INTEGER PRIMARY KEY AUTOINCREMENT, CURNAME TEXT, CURRATE TEXT, LASTUPDATETIME LONG)");
    }

    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
        if (oldVersion < 2) {
            db.execSQL("ALTER TABLE " + TB_NAME + " ADD COLUMN LASTUPDATETIME LONG DEFAULT 0");
        }
    }
}